Reactive nonionic surfactant having vinyl group and propylene oxide group and pressure-sensitive adhesive composition containing the same

Abstract

The present invention relates to a surfactant for an adhesive, an adhesive composition containing the same, and a method for producing the same. Since the surfactant of the present invention is contained in an adhesive and exhibits excellent adhesive strength and heat resistance retention, it can be widely applied to the production of adhesives.

Description

Technical Field

[0001] The present invention relates to a surfactant for adhesives and an adhesive composition containing the same, and particularly to a reactive nonionic surfactant for adhesives having a vinyl group and a PO (propylene oxide) group, an adhesive composition containing the same, and a method for producing the same.

Background Art

[0002] Conventionally, most of the adhesives commonly used are solvent-based adhesives produced using a volatile organic solvent as a solvent. However, as the industry becomes more advanced, environmental regulations are gradually strengthened, and when using a volatile organic solvent, many environmental problems occur. Therefore, in the field of adhesives, there is an increasing demand for adhesives with fewer environmentally harmful components.

[0003] Due to such demands, recently, aqueous or solventless adhesives using water as a solvent instead of solvent-based adhesives have been developed.

[0004] Aqueous adhesives are used for labels, tapes for electrical and electronics, tapes for construction and interior, tapes for automobiles, other tapes, medical use, etc. In the label market, more than 80% of the aqueous type is used. In the tape market excluding electrical and electronics, it is also manufactured by an emulsion polymerization method using an aqueous agent, a leveling agent, etc. The emulsion polymerization method is a method of polymerizing a water-insoluble monomer or a monomer with low solubility in water using the solubilization, emulsification, and dispersion functions of a surfactant.

[0005] Such aqueous adhesives have a problem that the adhesive physical properties such as initial adhesive strength, peel strength, and holding strength are significantly inferior to those of solvent-based adhesives in terms of performance, and additives such as surfactants used during emulsion polymerization are pointed out as the main cause.

[0006] In this regard, Patent Document 1 relates to an adhesive composition containing an acrylic copolymer, water, and a surfactant, and presents various sulfate-form anionic surfactants as the surfactant.

[0007] In the development of water-based adhesives, in order to solve problems such as environmental regulations and deterioration of resin physical properties, some multinational companies are trying to utilize special surfactants (reactive emulsifiers, polymer emulsifiers, etc.) in emulsion polymerization instead of general emulsifiers to improve initial adhesiveness, cohesion, and water resistance. However, due to problems such as aggregation, unreacted emulsifiers, and bubble generation depending on the form of the reactive emulsifier, the need to develop appropriate emulsifiers is increasing.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The surfactant for adhesives of the present invention was devised to solve the above problems, and is a surfactant for adhesives containing a compound represented by the following formula (1)

Chemical Formula

[0010] Another object of the present invention is to provide an adhesive composition containing the surfactant for adhesives of the present invention, an acrylic monomer, an initiator, and an aqueous solvent.

[0011] Furthermore, the present invention includes the following steps and is represented by the following formula (1) [Chemical formula] (In the formula, n is 9 to 15, 10 to 14, or 11 to 13, m is 1 to 7, 2 to 6, or 3 to 5, and R is an unsaturated hydrocarbon having 1 to 6, 2 to 5, or 3 to 4 carbon atoms.) A method for producing a surfactant for an adhesive, (a) The following formula (2) [Chemical formula] (In the formula, n is 9 to 15, 10 to 14, or 11 to 13, and m is 1 to 7, 2 to 6, or 3 to 5) A step of reacting a compound represented by the formula with an unsaturated carboxylic acid RCOOH (where R is an unsaturated hydrocarbon having 1 to 6, 2 to 5, or 3 to 4 carbon atoms); (b) A step of adding a catalyst after the reaction in step (a); (c) A step of adding a basic solution to the product of step (b) to neutralize it; (d) A step of obtaining an oil phase layer after layer-separating the product of step (c); and (e) A step of removing the solvent from the oil phase layer; Another object is to provide a manufacturing method including.

[0012] Furthermore, the present invention provides (A) an aqueous solvent, the following formula (1) [Chemical formula] (In the formula, n is 9 to 15, 10 to 14, or 11 to 13, m is 1 to 7, 2 to 6, or 3 to 5, and R is an unsaturated hydrocarbon having 1 to 6, 2 to 5, or 3 to 4 carbon atoms.) A step of mixing a surfactant for an adhesive, an anionic reactive surfactant, and acrylic acid represented by the formula, (B) A step of mixing an acrylic monomer with the mixture of step (A) to form a pre-emulsion, (C) A step of mixing an initiator and sodium metabisulfite with a part of the pre-emulsion, (D) A step of dropping the remaining pre-emulsion into the mixture of step (C), and (E) Another object is to provide a method for producing an adhesive composition including a neutralization step.

[0013] In addition to the above-mentioned clear objects, the object of the present invention can also be to achieve these objects and other objects that can be easily derived by those skilled in the art from these objects and the general technology of this specification.

Means for Solving the Problems

[0014] In order to achieve the above-mentioned objects, the surfactant for adhesives of the present invention has the following formula (1)

Chemical Formula

[0015] Further, the R may be a linear or branched hydrocarbon containing one unsaturated bond.

[0016] On the other hand, the adhesive composition of the present invention is characterized by containing the surfactant for adhesives of the present invention, an acrylic monomer, an initiator, and an aqueous solvent.

[0017] Further, the adhesive composition may further contain an anionic reactive surfactant. Also, based on 100 parts by weight of the acrylic monomer, 0.01 to 5 parts by weight, 0.05 to 1 part by weight, or 0.1 to 0.5 part by weight of the surfactant for adhesives, and 0.01 to 5 parts by weight, 0.05 to 1 part by weight, or 0.1 to 0.5 part by weight of the anionic reactive surfactant may be included.

[0018] Further, the anionic reactive surfactant may be a polyoxyethylene-based anionic surfactant having a vinyl group at the terminal.

[0019] Further, the anionic reactive surfactant may have a sulfonic acid or sulfonate functional group.

[0020] Further, the anionic reactive surfactant may be represented by the following formula (3) [Chemical formula] (wherein R' is alkyl, r is 5 to 45, 10 to 40, or 24 to 30, and X is SO3NH4 or SO3Na).

[0021] Furthermore, the acrylic monomer may be selected from the group consisting of acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and mixtures thereof.

[0022] Also, the acrylic monomer 1 part by weight of acrylic acid, 20 to 45 parts by weight, 22 to 40 parts by weight, or 24 to 38 parts by weight of 2-ethylhexyl acrylate, 25 to 70 parts by weight, 30 to 65 parts by weight, or 36 to 62 parts by weight of n-butyl acrylate, and 8 to 38 parts by weight, 10 to 30 parts by weight, or 12 to 28 parts by weight of methyl methacrylate may be included.

[0023] Also, the initiator may be ammonium persulfate or sodium metabisulfite.

[0024] Further, the pressure-sensitive adhesive composition may further contain one or more additives selected from the group consisting of tackifiers, emulsifiers, defoamers, stabilizers, pH adjusters, smoothing agents, wetting agents, and biocides.

[0025] Also, the pressure-sensitive adhesive may be used for one or more applications selected from the group consisting of labels, electrical / electronic tapes, architectural / interior tapes, automotive tapes, and medical adhesives.

[0026] On the other hand, the following formula (1) of the present invention [Chemical formula] (In the formula, n is 9 - 15, 10 - 14, or 11 - 13; m is 1 - 7, 2 - 6, or 3 - 5; and R is an unsaturated hydrocarbon having 1 - 6, 2 - 5, or 3 - 4 carbon atoms.) The method for producing a surfactant for an adhesive represented by (a) The following formula (2) [Chemical formula] (In the formula, n is 9 - 15, 10 - 14, or 11 - 13; m is 1 - 7, 2 - 6, or 3 - 5) and an unsaturated carboxylic acid RCOOH (where R is an unsaturated hydrocarbon having 1 - 6, 2 - 5, or 3 - 4 carbon atoms) are reacted; (b) After the reaction in step (a), a catalyst is added; (c) A basic solution is added to the product of step (b) for neutralization; (d) After layer separation of the product of step (c), an oil - phase layer is obtained; and (e) A solvent is removed from the oil - phase layer. It is characterized by including the above steps. Furthermore, R may be a linear or branched hydrocarbon containing one unsaturated bond.

[0027] Also, the unsaturated carboxylic acid may be 3 - butenoic acid, 3 - pentenoic acid, 4 - pentenoic acid, 2 - methyl - 3 - butenoic acid, 3 - hexenoic acid, 4 - hexenoic acid, 5 - hexenoic acid, 4 - methyl - 3 - pentenoic acid, 4 - methyl - 4 - pentenoic acid, 3 - methyl - 3 - pentenoic acid, 3 - methyl - 4 - pentenoic acid, 3 - ethyl - 3 - butenoic acid, 2 - methyl - 3 - pentenoic acid, 2 - methyl - 4 - pentenoic acid, 2,2 - diethyl - 3 - butenoic acid, 2,3 - diethyl - 3 - butenoic acid, or 2 - ethyl - 3 - butenoic acid.

[0028] Also, the catalyst in step (b) may be p - toluenesulfonic acid.

[0029] Further, the step (a) can be carried out by reacting at 40 to 80°C for 120 to 240 minutes.

[0030] Further, the step (b) can be carried out by reacting at 60 to 100°C for 84 to 108 hours.

[0031] Further, the step (c) can be carried out by neutralizing at 50 to 90°C for 12 to 36 hours.

[0032] On the other hand, the method for producing the pressure-sensitive adhesive composition according to the present invention is (A) A step of mixing an aqueous solvent, a surfactant for pressure-sensitive adhesives represented by the following formula (1) [Chemical formula] (wherein n is 9 to 15, 10 to 14, or 11 to 13, m is 1 to 7, 2 to 6, or 3 to 5, and R is an unsaturated hydrocarbon having 1 to 6, 2 to 5, or 3 to 4 carbon atoms), an anionic reactive surfactant, and acrylic acid; (B) A step of mixing an acrylic monomer with the mixture of the step (A) to form a pre-emulsion; (C) A step of mixing an initiator with a part of the pre-emulsion; (D) A step of dropping the remaining pre-emulsion into the mixture of the step (C); and (E) A step of neutralizing, which is characterized by including these steps.

[0033] Further, the acrylic monomer may be selected from the group consisting of n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and mixtures thereof.

[0034] Further, dodecyl mercaptan may be added in the step (B).

[0035] Further, the initiator in the step (C) may be ammonium persulfate.

[0036] Further, in the step (C), sodium metabisulfite may be further added.

[0037] Also, in the step (D), an initiator may be further added after the dropping.

[0038] Further, in the step (E), a mixture of an aqueous solvent and aqueous ammonia may be added to neutralize to a weak acidity.

[0039] Furthermore, a step of filtration may be included after the neutralization.

Advantages of the Invention

[0040] The surfactant for an adhesive of the present invention is a reactive nonionic surfactant, and when it is contained and used in an adhesive, particularly an aqueous adhesive, it has appropriate viscosity and average particle size, and can exhibit excellent coating physical properties and adhesive physical properties.

[0041] Also, according to the present invention, an aqueous adhesive composition excellent in both peel strength and heat retention can be provided.

[0042] Furthermore, according to the present invention, layer separation does not occur during pre-emulsion production, and no bubbles or aggregates are generated during adhesive emulsion production, and an adhesive composition of excellent quality can be produced.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail. However, the following is a detailed description by way of illustration of specific embodiments, and the present invention can be variously modified and can have various forms, so the present invention is not limited to the specific embodiments exemplified. It should be understood that the present invention includes all modifications, equivalents, or alternatives included within the spirit and technical scope of the present invention.

[0045] In addition, in the following description, many specific matters such as specific components are described, but these are provided to assist in a more overall understanding of the present invention, and it will be obvious to those skilled in the art that the present invention can be practiced even without these specific matters. Also, when it is determined that a detailed description of a related known function or configuration would unnecessarily obscure the gist of the invention in the description of the present invention, the detailed description thereof is omitted.

[0046] The terms used in the present application are merely used to describe specific embodiments and are not intended to limit the present invention. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art. Commonly used terms that are pre-defined as such should be interpreted to have a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or overly formal sense unless clearly defined in the present application.

[0047] In the present application, singular expressions include plural expressions unless the context clearly dictates otherwise.

[0048] In this application, terms such as "comprising", "containing", or "having" refer to the presence of the features, components (or constituents), etc. described in the specification, and do not mean that one or more other features, components, etc. do not exist or cannot be added.

[0049] The surfactant for an adhesive of the present invention is characterized in that, as a nonionic reactive surfactant, it contains a compound represented by the following formula (1). In particular, the surfactant for an adhesive of the present invention is characterized by containing repeating units of ethylene oxide (EO) and propylene oxide (PO).

Chemical formula

[0050] When the ranges of n, m, and R are less than the above ranges, during the production of pre-emulsion, a small amount of layer separation may occur, and although the emulsion production proceeds, a poor emulsion stability phenomenon may appear. On the other hand, when the ranges of n, m, and R exceed the above ranges, layer separation may occur due to poor emulsification during the production of pre-emulsion, and in some cases, the emulsion cannot be produced.

[0051] The above R may be a linear or branched hydrocarbon containing one or more, preferably one, unsaturated bond (C=C). This may be derived from an unsaturated carboxylic acid that is a reactant during the production of the nonionic reactive surfactant. The unsaturated bond can be present at the end. Also, the unsaturated carboxylic acid may not be acrylic acid or its derivative. The unsaturated carboxylic acid can be characterized by having an sp 3 hybridization, which means that the unsaturated bond C=C double bond and the C=O double bond are not conjugated.

[0052] On the one hand, the pressure-sensitive adhesive composition of the present invention is characterized by containing the surfactant for pressure-sensitive adhesives of the present invention, an acrylic monomer, an initiator, and an aqueous solvent, and may be an aqueous pressure-sensitive adhesive composition. The surfactant for pressure-sensitive adhesives can contain 0.01 to 5 parts by weight, 0.05 to 1 part by weight, or 0.1 to 0.5 part by weight based on 100 parts by weight of the acrylic monomer.

[0053] In addition, the pressure-sensitive adhesive composition can further contain an anionic reactive surfactant. By combining the surfactant for pressure-sensitive adhesives according to the present invention, which is a nonionic reactive surfactant, with an anionic reactive surfactant, the adhesiveness can be significantly improved. In this case, based on 100 parts by weight of the acrylic monomer, the surfactant for pressure-sensitive adhesives can contain 0.01 to 5 parts by weight, 0.05 to 1 part by weight, or 0.1 to 0.5 part by weight, and the anionic reactive surfactant can contain 0.01 to 5 parts by weight, 0.05 to 1 part by weight, or 0.1 to 0.5 part by weight. The weight ratio of the nonionic reactive surfactant to the anionic reactive surfactant is preferably 3:7 to 7:3, 4:6 to 6:4, or 4.5:5.5 to 5.5:4.5. When the content of the nonionic reactive surfactant is less than the above range, the heat resistance may decrease, and when it exceeds the above range, poor emulsification may occur. Also, when the content of the anionic reactive surfactant is less than the above range, the emulsion stability may decrease, and when it exceeds the above range, the water resistance may decrease.

[0054] The anionic reactive surfactant may be a polyoxyethylene-based anionic surfactant having a vinyl group at the end. In particular, the anionic reactive surfactant can have a sulfonic acid or sulfonate functional group. As an example, the anionic reactive surfactant can be represented by the following formula (3).

Chemical formula

[0055] Also, the acrylic monomer can be selected from the group consisting of acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and mixtures thereof.

[0056] Specifically, the acrylic monomer can include 1 part by weight of acrylic acid, 20 to 45 parts by weight, 22 to 40 parts by weight, or 24 to 38 parts by weight of 2-ethylhexyl acrylate, 25 to 70 parts by weight, 30 to 65 parts by weight, or 36 to 62 parts by weight of n-butyl acrylate, and 8 to 38 parts by weight, 10 to 30 parts by weight, or 12 to 28 parts by weight of methyl methacrylate.

[0057] The acrylic monomer includes, but is not limited to, alkyl acrylates or alkyl methacrylates having 3 or less carbon atoms in the alkyl group such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isopropyl acrylate, and isopropyl methacrylate; cyclic alkyl (meth)acrylates such as cyclohexyl (meth)acrylate; aromatic (meth)acrylates such as phenoxymethyl (meth)acrylate and benzyl (meth)acrylate; aliphatic (meth)acrylates such as hydroxyalkyl acrylate, hydroxyalkyl methacrylate, polyoxyethylene (meth)acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, glycidyl acrylate, and glycidyl methacrylate; (meth)acrylamides such as acrylamide, methacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, and N-methoxybutylacrylamide; radical polymerizable monomers containing an aldehyde group and / or a ketone group such as vinyl methyl ketone, vinyl ethyl ketone, vinyl-n-propyl ketone, vinyl-i-propyl ketone, vinyl-n-butyl ketone, vinyl-i-butyl ketone, vinyl-t-butyl ketone, vinyl phenyl ketone, vinyl benzyl ketone, divinyl ketone, and diacetoneacrylamide; nitrile group-containing unsaturated compounds such as (meth)acrylonitrile, crotononitrile, 2-cyanoethyl (meth)acrylate, 2-cyanopropyl (meth)acrylate, and 3-cyanopropyl (meth)acrylate; monovinyl aromatic compounds such as styrene, o-vinyltoluene, m-vinyltoluene, p-vinyltoluene, p-ethylvinylstyrene, α-methylstyrene, and α-fluorostyrene; vinyl halides such as vinyl chloride and vinylidene chloride; and vinyl esters such as vinyl propionate.

[0058] The initiator may be ammonium persulfate, sodium metabisulfite, or a mixture thereof, but is not limited thereto. The initiator for the adhesive can be used without limitation, such as thermal decomposition initiators and redox initiators, and potassium persulfate or sodium hydrogen sulfite can also be used.

[0059] In addition, the aqueous adhesive composition may further contain one or more additives selected from the group consisting of tackifiers, emulsifiers, defoamers, stabilizers, pH adjusters, smoothing agents, wetting agents, and biocides. In addition to the above-mentioned additives and components, other additives or components can be appropriately further included according to the use of the adhesive.

[0060] Further, the adhesive can be used for one or more applications selected from the group consisting of labels, electrical and electronic tapes, architectural and interior tapes, automotive tapes, and medical adhesives.

[0061] The aqueous adhesive composition of the present invention is an adhesive composition having excellent peel strength (adhesive force) and heat resistance retention. When the peel strength is measured using a 1 kg grip and the heat resistance retention is measured through the pushed distance (mm) with a 1 kg weight attached at 80°C for 1 hour, the peel strength (kg f / inch) may be 1.4 - 2.5, 1.42 - 2.2, or 1.45 - 2, and the heat resistance retention may be 0.5 mm or less, 0.3 mm or less, or 0.15 mm or less.

[0062] The aqueous adhesive composition of the present invention may have an average particle size of 300-600 nm, 400-600 nm, or 500-550 nm, and a viscosity of 150-400 cP, 180-350 cP, or 200-300 cP. The particle size of the adhesive is influenced by the type and concentration of the surfactant, and exhibits monomolecular properties. If the particle size is less than the above range, the particle stability may deteriorate, and if it exceeds the above range, the coating properties and adhesive properties may deteriorate.

[0063] On the other hand, the compound represented by the following formula (1) of the present invention [ka] (wherein n is 9 to 15, 10 to 14, or 11 to 13, m is 1 to 7, 2 to 6, or 3 to 5, and R is an unsaturated hydrocarbon having 1 to 6, 2 to 5, or 3 to 4 carbon atoms), (a) The following formula (2) [ka] (wherein n is 9 to 15, 10 to 14, or 11 to 13, and m is 1 to 7, 2 to 6, or 3 to 5) is reacted with an unsaturated carboxylic acid RCOOH (wherein R is an unsaturated hydrocarbon having 1 to 6, 2 to 5, or 3 to 4 carbon atoms); (b) after the reaction of the step (a), adding a catalyst; (c) neutralizing the product of the step (b) by adding a basic solution; (d) obtaining an oil phase layer after layer separation of the product of the step (c); and (e) removing the solvent from the oil phase layer.

[0064] The R may be a straight or branched chain hydrocarbon containing one or more, preferably one, unsaturated bond (C=C).

[0065] The unsaturated carboxylic acid may be 3-butenoic acid, 3-pentenoic acid, 4-pentenoic acid, 2-methyl-3-butenoic acid, 3-hexenoic acid, 4-hexenoic acid, 5-hexenoic acid, 4-methyl-3-pentenoic acid, 4-methyl-4-pentenoic acid, 3-methyl-3-pentenoic acid, 3-methyl-4-pentenoic acid, 3-ethyl-3-butenoic acid, 2-methyl-3-pentenoic acid, 2-methyl-4-pentenoic acid, 2,2-diethyl-3-butenoic acid, 2,3-diethyl-3-butenoic acid, or 2-ethyl-3-butenoic acid.

[0066] The step (a) can react at 40 to 80 °C for 120 to 240 minutes. And the step (b) can react at 60 to 100 °C for 84 to 108 hours. The catalyst for the step (b) may be p-toluenesulfonic acid (p-TsOH). The step (c) can neutralize at 50 to 90 °C for 12 to 36 hours. The step (d) can be fractionated by dissolving in DCM (dichloromethane) after removing the solvent and mixing with D.W (distilled water) (0.1 to 1 M Na2CO3). Then, the aqueous layer is washed with DCM, and after obtaining the DCM layer, sodium sulfate (Na2SO 4 ) is added to remove residual water, and it can be removed by filtration under reduced pressure to remove sodium sulfate. The step (e) can remove the solvent with a rotary evaporator at 40 to 60 °C. After the step (e), a step of drying at 40 to 60 °C can further be included.

[0067] In the steps (a) to (e), when produced beyond the above ranges, there may be cases of overreaction, insufficient reaction, and failure to exhibit the characteristics as a surfactant.

[0068] On the other hand, the method for producing the adhesive composition according to the present invention comprises (A) an aqueous solvent, the following formula (1)

Chemical formula

[0069] Hereinafter, each step will be described in detail. First, step (A) is the step of mixing an aqueous solvent, the surfactant for an adhesive represented by the formula (1), and acrylic acid. At this time, an anionic reactive surfactant can be further included and mixed. As described above, the anionic reactive surfactant may be a polyoxyethylene-based anionic surfactant having a vinyl group at the terminal. In particular, the anionic reactive surfactant can have a sulfonic acid or sulfonate functional group.

[0070] Next, step (B) is the step of mixing an acrylic monomer with the mixture of step (A) to form a pre-emulsion. Stir for 20 to 40 minutes until a milky white emulsion is formed. At this time, the acrylic monomer is as described above, and in particular, it can be selected from the group consisting of n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and mixtures thereof. The acrylate monomer can be added so as to contain 0.01 to 5 parts by weight, 0.05 to 1 part by weight, 0.1 to 0.5 parts by weight of the nonionic reactive surfactant and 0.01 to 5 parts by weight, 0.05 to 1 part by weight, 0.1 to 0.5 parts by weight of the anionic reactive surfactant per 100 parts by weight of the acrylate monomer.

[0071] In the step (B), dodecyl mercaptan can be added, and the molecular weight can be adjusted during the production of the emulsion (molecular weight adjustment of high molecular polymerization). Dodecyl mercaptan can be added in an amount of 0.01 to 0.1 part by weight, 0.02 to 0.08 part by weight, or 0.03 to 0.07 part by weight based on 100 parts by weight of the acrylate monomer.

[0072] Next, the step (C) is a step of mixing an initiator into a part of the pre-emulsion. The initiator in the step (C) may be ammonium persulfate. This may be for a preliminary reaction. Further, sodium metabisulfite (SMBS) can be added in the step (C).

[0073] More specifically, the step (C) can include: (C-1) a step of adding a mixture of an aqueous solvent and an initiator to a part of the pre-emulsion and stirring; and (C-2) a step of adding the product of the step (C-1), the mixture of the aqueous solvent and the initiator, and sodium metabisulfite (SMBS) to a reaction vessel heated to 70 to 90 °C in sequence and then stirring.

[0074] Next, the step (D) is a step of dropping the remaining pre-emulsion into the mixture in the step (C). The dropping can be carried out for 1 to 3 hours or 1.5 to 2.5 hours. After the dropping, an initiator or a mixture of an initiator and an aqueous solvent can be further added. Then, the temperature can be maintained at 32 to 35 °C.

[0075] Next, the step (E) is a neutralization step. A basic solution such as a mixture of an aqueous solvent and aqueous ammonia can be added to the product in the step (D) to neutralize it to a weakly acidic state (pH 5 to 6). After neutralization, filtration can be carried out to obtain an aqueous pressure-sensitive adhesive composition.

[0076] Hereinafter, examples of the present invention will be described. Examples Production Example 1: Synthesis of a Reactive Nonionic Surfactant 100 g (0.12 mol) of 2-allyloxy-EO(12)-PO(3)-propanol (2-allyloxy-EO(12)-PO(3)-propanol), 250 mL of benzene, and 20.657 g (0.24 mol) of 3-butenoic acid were added and mixed in a 1000 mL cylindrical three-necked flask, and then reacted at 60 °C for 3 hours. Then, 1.237 g (0.0072 mol) of the catalyst p-TsOH was added and reacted at 80 °C for 96 hours. After the reaction was completed, 13.47 g (0.1272 mol) of Na2CO3 was added and reacted at 70 °C for 24 hours to neutralize the catalyst. After removing the solvent from the neutralized solution at 50 °C using a rotary evaporator, it was dissolved in 1000 mL of DCM, and then mixed with 1000 mL (0.5 M Na2CO3) of D.W and fractionated. The aqueous layer was washed 3 times with DCM to obtain a DCM layer. Then, 5 g of Na2SO4 was added to remove the remaining water, and it was filtered under reduced pressure to remove Na2SO4. The product was dried at 50 °C using a rotary evaporator to remove the solvent and then dried in a vacuum oven at 50 °C to produce 2-allyloxy-EO(12)-PO(3)-butenoate (2-allyloxy-EO(12)-PO(4)-3-butenoate; AAE_0825A) represented by the following formula (4).

Chemical formula

[0077] Test Example 1: Confirmation of synthesis of reactive nonionic surfactant - 1 H NMR The presence or absence of the synthesis of the reactive nonionic surfactant produced in Production Example 1 was 1 confirmed by 1H NMR (Figure 1). As shown in Figure 1, after adding the catalyst p-TsOH, the yield can be predicted from the peak e that appears (yield = (integration of e) × 100). Thereby, the synthesis of the reactive nonionic surfactant was confirmed, and it was confirmed that the yield was 80%.

[0078] Test Example 2: Confirmation of synthesis of reactive nonionic surfactant - 13 13C NMR The presence or absence of the synthesis of the reactive nonionic surfactant produced in Production Example 1 was 13Confirmed by \(^{13}\)C NMR (Figure 2). As shown in Figure 2, after adding the catalyst p-TsOH, the synthesis proceeded, and the p, q, r, s peaks of 3-butenoic acid and the synthesized l, m, n, o peaks were measured. It was confirmed that there was no residual 3-butenoic acid (p, q, r, s peaks) in the product after neutralization. Also, before adding the catalyst p-TsOH, the synthesis did not proceed, and there were no i, j peaks after synthesis, only the i, j peaks of the reactants were present. It was confirmed that the i, j peaks synthesized after adding the catalyst were formed.

[0079] Example 1: Production of Adhesive Composition (1) Add 34.83 phr of D.W to a four-necked round-bottom flask and heat to 80 °C to create a polymerization atmosphere. In a beaker, add 26.29 phr of D.W, 0.35 phr of an anionic reactive surfactant (SR-3025, manufactured by ADEKA), 0.35 phr of the reactive nonionic surfactant (2-allyloxy-EO(12)-PO(4)-3-butenoate) produced in Production Example 1 above, and 1.00 phr of acrylic acid (AA), and then stir using a mechanical stirrer. Add 37.5 phr of 2-ethylhexyl acrylate (2-EHAM), 37.5 phr of n-butyl acrylate (BAM), 24.0 phr of methyl methacrylate (MMA), and 0.044 phr of dodecyl mercaptan to the beaker and stir. When a milky white emulsion was formed, stir for 30 minutes. In the beaker, mix 2.78 phr of D.W and 0.28 phr of ammonium persulfate (APS), then add it to the pre-emulsion and stir for 5 minutes.

[0080] Add 1.39 phr of the generated pre-emulsion, a mixture of 0.44 phr of D.W and 0.017 phr of APS, and 0.009 phr of sodium metabisulfite (SMBS) to the four-necked round-bottom flask in order, and stir for 5 minutes. Then, after adding the remaining pre-emulsion to a cylindrical dropping panel, drop it over 2 hours. After the dropping is complete, further add 0.17 phr of D.W and 0.053 phr of APS, replace the tap water in the water bath, and maintain the temperature at 32 - 35 °C. Add a mixture of 0.26 phr of D.W and 0.26 phr of 25% aqueous ammonia to neutralize to a weak acidity, and filter with a filter cloth after 10 minutes.

[0081] Example 2: Production of Adhesive Composition (2) It was produced in the same manner as in Example 1, but an adhesive composition was produced by changing the ratio of monomers to 2-EHAM 25.5 phr, BAM 59.5 phr, and MMA 14.0 phr.

[0082] Comparative Example 1: Production of Adhesive Composition (3) It was produced in the same manner as in Example 1, but an adhesive composition was produced using 2-allyloxy-EO(11)-3-butenoate (AAE_550A) represented by the following formula (5) instead of the reactive nonionic surfactant 2-allyloxy-EO(12)-PO(4)-3-butenoate (AAE_0825A) produced in Production Example 1. [Chemical formula]

[0083] Comparative Example 2: Production of Adhesive Composition (4) It was produced in the same manner as in Example 1, but an adhesive composition was produced by changing the ratio of monomers to 2-EHAM 25.5 phr, BAM 59.5 phr, and MMA 14.0 phr using 2-allyloxy-EO(11)-3-butenoate (AAE_550A) instead of the reactive nonionic surfactant 2-allyloxy-EO(12)-PO(4)-3-butenoate (AAE_0825A) produced in Production Example 1.

[0084] Test Example 3: Analysis of Adhesive Composition When analyzing the physical and chemical properties of the surfactants used in Examples 1 and 2 and Comparative Examples 1 and 2 and the adhesive compositions produced using the surfactants, the results were as shown in Tables 1 and 2 below. Also, the analysis results for particle size were the same as in Figure 5 and Table 3. [Table 1] [Table 2] In Table 2 above, each item was measured and calculated as follows. NV, Conversion rate: After drying the D.W. and monomer remaining in an oven at 120°C, calculate NV = (W d / W s ) × 100 (%) Conversion rate = (W d / W s T s ) × 100 (%) Wd = Weight of the sample after drying Ws = Weight of the sample before drying Ts = Ideal solid content (%) Peel strength: Using a 1 kg grip Heat resistance retention: Distance pressed for 1 hour with a 1 kg weight at 80°C Particle size: Using a zetasizer Layer separation: A phenomenon caused by insufficient surfactant during pre - emulsion production

Table 3

[0085] Through the above experiments, compared with Comparative Examples 1 and 2 of the adhesive emulsion produced using a non - ionic reactive surfactant (AAE_550A) having only EO repeating units, in the case of Examples 1 and 2 which are adhesive emulsions produced using a non - ionic reactive surfactant (AAE_0825A) containing both EO and PO repeating units, it can be seen that the peel strength and heat resistance retention are significantly improved.

[0086] As described above, the preferred embodiments of the present invention have been explained. However, the present invention is not limited to the specific embodiments described above. Of course, those skilled in the art can make various modifications without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the above embodiments, but should be determined not only by the claims described below, but also by those equivalent to this claim scope.

Claims

1. The following formula (1) 【Chemical 1】 (In the formula, n is 9 to 15, m is 1 to 7, and R is an unsaturated hydrocarbon having 1 to 6 carbon atoms.) A surfactant for an adhesive, comprising a compound represented by the formula.

2. An adhesive composition comprising the surfactant for an adhesive according to Claim 1, an acrylic monomer, an initiator, and an aqueous solvent.

3. The adhesive composition according to Claim 2, further comprising an anionic reactive surfactant.

4. The adhesive composition according to Claim 2, wherein the acrylic monomer is selected from the group consisting of acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and mixtures thereof.

5. The adhesive composition according to Claim 2, further comprising one or more additives selected from the group consisting of a tackifier, an emulsifier, an antifoaming agent, a stabilizer, a pH adjuster, a smoothing agent, a wetting agent, and a biocide.

6. The adhesive composition according to Claim 2, which is used for one or more applications selected from the group consisting of labels, electrical / electronic tapes, architectural / interior tapes, automotive tapes, and medical adhesives.

7. A method for producing a surfactant for an adhesive represented by the following formula (1) 【Chemical formula 2】 (In the formula, n is 9 to 15, m is 1 to 7, and R is an unsaturated hydrocarbon having 1 to 6 carbon atoms.), comprising the following steps: (a) Reacting a compound represented by the following formula (2) 【Chemical Formula 3】 (In the formula, n is 9 to 15, m is 1 to 7) with an unsaturated carboxylic acid RCOOH (where R is an unsaturated hydrocarbon having 1 to 6 carbon atoms); (b) Adding a catalyst after the reaction in step (a); (c) Adding a basic solution to the product of step (b) to neutralize it; (d) After separating the layers of the product of step (c), obtaining an oil phase layer; and (e) Removing the solvent from the oil phase layer.

8. (A) A step of mixing an aqueous solvent, a surfactant for an adhesive represented by the following formula (1) 【Chemical Formula 4】 (In the formula, n is 9 to 15, m is 1 to 7, and R is an unsaturated hydrocarbon having 1 to 6 carbon atoms), an anionic reactive surfactant, and acrylic acid, (B) A step of mixing an acrylic monomer with the mixture of step (A) to form a pre-emulsion, (C) A step of mixing an initiator with a part of the pre-emulsion. (D) A step of dropping the remaining pre-emulsion into the mixture of the step (C), and (E) A step of neutralizing, A method for producing an adhesive composition.

9. The method for producing an adhesive composition according to claim 8, wherein the acrylic monomer is selected from the group consisting of n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and mixtures thereof.

Images